A Guide to Glass Entrances and Wall Systems

Joe Schiavone
September 5, 2014
COMMERCIAL

C.R. Laurence Clear View glass wall office system with CRL 24-inch back-to-back ladder pulls. Photo by A. Warner – IKM Architects

Amid a push toward large, open spaces in the workplace, more people are working in
glass offices or conference rooms than ever before. Roughly 68 percent of U.S. offices have an “open plan” or “open seating” design, with work surfaces separated by low or no walls. The remaining offices and conference rooms are often walled in glass, creating an optimal balance of private and collaborative spaces to fulfill multiple functions.

Glass walls and doors in offices offer better communication and collaboration, improved energy performance, more natural light, contemporary aesthetics and expansive views. The
benefits have made glass wall office fronts an attractive solution for office interiors, and companies working in the commercial interiors industry must understand the capabilities and limitations of the various options available.

Design considerations

First, consider the following questions when designing with glass wall office systems:

  • What is the primary function of the space for the end user (office front, conference room, lobbies, etc.)?
  • What are the Americans with Disabilities Act requirements for the project?
  • Are there any fire egress requirements to consider?
  • Are there any fire-rating requirements?
  • Is a Sound Transmittance Coefficient rating required?

The answers to these questions will affect the design and can add cost and lead time to a project if not incorporated into the plan from the beginning. By identifying and addressing each of these issues, and having a strong grasp on the different system types, a glazing contractor will be able to design and build functional, attractive and codecompliant glass wall office systems every time.

Glass door types

The Glass Association of North America has identified four standard types of heavy glass tempered doors: “A,” “P,” “BP,” and “F.”

Type “A” Doors require patch fittings at both top and bottom. GANA recommends that this door type not exceed 102 inches in height (with ½-inch glass). It is most commonly used in interior applications where minimal architectural hardware is desired, or in openings where a glass transom is located directly above the door. This is the most frequently used type of door in an office front application.

Type “P” Doors have a full-length top and bottom rail. The door is most commonly used with an overhead concealed closure. It is used when the height and weight limitations exceed that of the “A” Type door. The maximum height recommended by GANA is 108 inches (with ½-inch glass). This is the second most popular type of door used in an office front application.

The “BP” Type has a full-length rail at the bottom with a patch fitting at the top. It is most commonly used with concealed floor closing devices. BP doors should not exceed 108 inches (with ½-inch glass). While this type of door isn’t used as often, the incorporation of a full-length bottom rail can satisfy Americans with Disabilities Act requirements, while retaining the contemporary all-glass aesthetic of a patch fitting at the top.

The “F” Type is the same as type “A,” with the addition of a patch lock at the bottom corner. This type of door is less frequently used in an office front application.

Office front applications

Office fronts can be either framed or frameless. Both can feature pivoting or sliding doors, and sidelites. The most common frameless look utilizes “A” or “P” Type doors with sidelites. These incorporate discreet “U” channels at the top and bottom. The doors are commonly used in either a free swing or overhead closure application, and the use of a stop applied at the header is recommended to keep these doors from swinging into the walkway outside of the office. A floor or wall stop is also recommended to keep the swing doors from hitting adjacent walls.

Designers often work around the unfavorable appearance of doorstops by specifying sliding doors in lieu of pivoting doors. This solves two problems: it prevents the door from swinging into a walkway, and it maximizes space utilization. A sliding door application can potentially save nine square feet of space, as compared to a pivoting door. This allows denser occupancy and reduces safety issues.

If security is a concern, locking mechanisms may be required for glass doors. A locking ladder pull is the most commonly used, and can be applied in both pivoting and sliding applications. A latch designed to work with glass is also common. This incorporates the sidelite as well as the door. The sidelite contains the latch keeper, and the door requires the actual latch with the locking mechanism.

Framed office fronts are available with many options in a range of configurations. The most common is a single door and a small sidelite. The door fits into framing that wraps around the sheetrock walls. This is a popular solution because the framing covers the rough opening and eliminates finishing, speeding up construction time for both the glazier and general contractor. Additionally, framed systems can accommodate fire-rated frames to provide heat barriers when required by code.

The doors are typically aluminum wide stile with glass infill. Wide stiles provide space within the door to accommodate the hardware for office fronts. An office lever latch, very similar to what is used on a wood door, is used in this type of application. A narrow or medium stile door would require different latch hardware, and therefore would not match the rest of the office door latches, creating an inconsistent look throughout the project.

Most office doors are free swing, which means they do not have a closing mechanism. A door stop is required to prevent them from hitting the wall, and if a closer is required, it is most often a flush mounted or applied closer. This is usually field applied and installed.

An all-glass door can also be used in the framed application. This door is also used in combination with butt-glazed glass in a framed opening, which creates long clear views in offices.

All of the door styles can be configured for sliding applications to save space and provide a more modern look.

Conference room applications

Bi-fold doors are often used to open or close a conference room, converting it into a multipurpose space. They can be configured to have operable doors at the ends, or they can be hinged to the bi-fold door. This gives the designer many options and configurations from which to choose.

Bi-fold doors do have width, height and weight limitations. Always refer to the manufacturer’s literature and requirements when designing or installing these openings.

Bi-fold doors are available in both framed and frameless options from various manufacturers. They are hung with a bottom track, which is usually recessed into the concrete or floor. This requires cutting, and may be undesirable for some applications. The track can also create a trip hazard.

A solution that eliminates these problems is a stacking glass partition system. These systems are top hung on a trolley and do not require a bottom track to be installed. The trolley moves and stops in many different configurations. Designers often prefer using these systems due to their versatility and simple design. Similar to bi-folding doors, stacking partition systems are available in both framed and frameless styles. Dustproof strikes are most commonly used to lock and secure the panels into a closed position.

A convertible door can be incorporated with a stacking partition system. The door will slide and park with the rest of the panels when an open door is not needed. It also provides access into the room or rooms when the panels are in a closed position. A permanent all glass door can also be used on either end of this application, creating an egress when required by code.

Bottom rolling sliding doors are the least common, in part because they require more space. These doors require multiple top and bottom tracks, and are sometimes referred to as “mall sliders,” as they are very commonly seen in that environment. The doors can be wider and taller than bi-fold or top-hung sliding glass partitions, making them an ideal solution for large openings with heavier doors.

The author is sales and marketing manager, strategic accounts, for C.R. Laurence Co., Inc., www.crlaurence.com. If there is a specific topic you’d like him to address in his “Tips of the Trade” article series, write him at joe_schiavone@crlaurence.com.